macvlan: export macvlan mode through netlink

In order to support all three modes of macvlan at
runtime, extend the existing netlink protocol
to allow choosing the mode per macvlan slave
interface.

This depends on a matching patch to iproute2
in order to become accessible in user land.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/if_link.h b/include/linux/if_link.h
index 1d3b242..6674791 100644
--- a/include/linux/if_link.h
+++ b/include/linux/if_link.h
@@ -181,4 +181,19 @@
 	__u32 to;
 };
 
+/* MACVLAN section */
+enum {
+	IFLA_MACVLAN_UNSPEC,
+	IFLA_MACVLAN_MODE,
+	__IFLA_MACVLAN_MAX,
+};
+
+#define IFLA_MACVLAN_MAX (__IFLA_MACVLAN_MAX - 1)
+
+enum macvlan_mode {
+	MACVLAN_MODE_PRIVATE = 1, /* don't talk to other macvlans */
+	MACVLAN_MODE_VEPA    = 2, /* talk to other ports through ext bridge */
+	MACVLAN_MODE_BRIDGE  = 4, /* talk to bridge ports directly */
+};
+
 #endif /* _LINUX_IF_LINK_H */